It is estimated that there are more than 100,000 businesses engaged in the occupation of applying window tint to vehicle windshields. Applying a vehicle tinted windshield visor is a time intensive, exacting operation. The purpose of window tint is generally to protect the interior and occupants from harmful ultraviolet rays and glare. Window tinting keeps vehicles cooler and more comfortable for the occupants and also has limited insulating qualities.
Additionally, “anti-shatter” film may be applied to glass with the primary benefit of reducing the risk of injury from cutting and piercing. Reducing damage to property is a secondary but important benefit. These films are made of heavy-gauge plastic and are intended to retain broken glass fragments when subject to impact.
Two broad categories of materials are most often used for window film. Polyester based products are used for all types of applications. Vinyl products are almost exclusively used within buildings.
Window tinting may be performed by the vehicle manufacturer, but is often performed by after-market specialists and occasionally by lay vehicle operators. The process generally includes: (1) cleaning the interior window; (2) covering the window with window film from the interior and securing it temporarily in place with a soap and water mixture; (3) physically cutting (or measuring to be cut) the window film to fit the area to be covered; (4) carefully removing the window film template; (5) applying the tinting film to the window; (6) removing any extraneous film material from the interior of the window and cleaning both the interior surface of the window and the surrounding vehicle, as necessary.
For many specialists and lay vehicle operators, cutting the window film to the correct dimensions is a difficult and time-consuming part of applying the window tint, particularly when cutting for front or rear windshields, which are typically arced or contoured.
In general, there are two methods used for cutting windshield tint that account for the curvature of the windshield so that material lies flat and does not wrinkle, buckle or come loose. The first method is to manually measure the dimensions of window film necessary, apply markings along those dimensions on the windshield itself (such as masking tape), position window film over applied markings and cut to the correct dimensions. A person can make a template using this model, to be used on cars having the same windshields. This process is time consuming for each vehicle and can require many templates to be efficient. Alternatively, a plotter (which is a tool that measures curves, prints and cuts) may be used to compensate for arc. A plotter is an extremely expensive, non-portable type of computer equipment (costing from $7,000-10,000) and there are limitations in programming that do not allow for variations in dimensions for all windshields on the market without distortion.
It is also important to note that vehicle window tinting is heavily regulated by state law. Automobile window tinting reduces the visible light transmission (VLT) through car windows and this diminishes night visibility. It also effects the ability of law enforcement, security and emergency personnel to be able to identify the passengers in a vehicle.
In particular, state visor laws regulate the width of the “visor portion” which is the strip of window tint applied to the front of a windshield. This width measurement is taken from the top of the windshield to the bottom of the visor portion (also known in the art as an “eyebrow”).
It is desirable to have an efficient, inexpensive tool to measure visors so that they are in compliance with state visor limit laws.
It is also desirable to have an efficient, inexpensive tool that mathematically compensates for the contour of a windshield for a wide range of makes and models of cars.